brms (version 1.1.0)

epilepsy: Epileptic seizure counts

Description

Breslow and Clayton (1993) analyse data initially provided by Thall and Vail (1990) concerning seizure counts in a randomised trial of anti-convulsant therapy in epilepsy. Covariates are treatment, 8-week baseline seizure counts, and age of the patients in years.

Usage

epilepsy

Format

A dataframe of 236 observations containing information on the following 9 variables.

Source

Thall, P. F., & Vail, S. C. (1990). Some covariance models for longitudinal count data with overdispersion. Biometrics, 46(2), 657-671. Breslow, N. E., & Clayton, D. G. (1993). Approximate inference in generalized linear mixed models. Journal of the American Statistical Association, 88(421), 9-25.

Examples

## Not run: 
# ## poisson regression without random effects. 
# fit1 <- brm(count ~ log_Age_c + log_Base4_c * Trt_c, 
#             data = epilepsy, family = poisson())
# summary(fit1) 
# plot(fit1)             
#     
# ## poisson regression with random intercepts of patients and visits
# ## as well as normal priors for fixed effects parameters.    
# fit2 <- brm(count ~ log_Age_c + log_Base4_c * Trt_c 
#             + (1|patient) + (1|visit), 
#             data = epilepsy, family = poisson(), 
#             prior = set_prior("normal(0,5)"))
# summary(fit2) 
# plot(fit2)
# ## End(Not run)